#159-Peter Hotez MD, PhD.: The anti-vaccine movement, causes of autism, & COVID-19 vaccine update

KEYPOINTS

• 01

  The anti-vaccine movement survives by moving the goalposts.

  Hotez, a vaccine scientist and pediatrician at Baylor, dates the modern movement to Andrew Wakefield's 1998 Lancet paper linking the MMR vaccine to autism. As each claim was refuted it shifted: to thimerosal, then to vaccine spacing, then aluminum, then vague 'chronic illness' and HPV-vaccine infertility claims. He calls these versions 1.0, 2.0 and 3.0; the autism thread never fully disappeared.

• 02

  The Wakefield claims collapsed, but slowly.

  By around 2007–2008 nearly every Wakefield claim had been debunked, and the Lancet retracted the paper in about 2010 after an earlier expression of concern. Attia stresses that open discussion won't dissuade the roughly 20% firmly convinced vaccines are evil; Hotez's goal is helping undecided parents.

• 03

  Thimerosal was removed before the autism hypothesis gained steam.

  Thimerosal, a preservative in multi-dose vials that contains ethylmercury (not the more toxic methylmercury), was proposed in 2001 as an autism cause. Hotez notes its removal from childhood vaccines was already underway around 1999, and that the 2001 hypothesis was reasonable to raise at the time—it just didn't hold up.

• 04

  Spacing out vaccines has no supporting evidence.

  Hotez says he isn't aware of data showing a benefit from delaying or spreading vaccines, and there are no trials supporting alternative schedules, while delays leave children unprotected during their most vulnerable months.

• 05

  The Hib vaccine shows how dramatic a vaccine's impact can be.

  As a pediatric resident at Massachusetts General in 1987–88, Hotez admitted a child with Haemophilus influenzae type b meningitis every couple of weeks. A conjugate vaccine attaching the bacterial capsule to a protein produced infant immune responses and was licensed in 1989; Hib meningitis became rare.

• 06

  HPV vaccination is cancer prevention.

  Several high-risk HPV strains, including 16 and 18, cause cervical and other cancers. Australia expects to eliminate cervical cancer by 2030 through vaccination. Attia, father of a 12-year-old girl, walks through a parent's instinct to wait until 18 and why vaccinating before any exposure gives the best protection.

• 07

  Autism begins in fetal brain development, not after vaccines.

  Hotez's daughter Rachel was diagnosed at 19 months; full clinical expression often appears around 18–24 months, which is why vaccines given then are falsely blamed. Brain changes are detectable in infancy (a UNC Chapel Hill group) and prenatally (Eric Courchesne's group at UCSD), and the Broad Institute has identified about 100 autism-linked genes involved in early fetal brain development, many in neuronal communication.

• 08

  Genetic testing explains only a portion of cases.

  Whole-exome sequencing finds a relevant mutation perhaps 30–40% of the time, reflecting non-coding and other factors. Hotez thinks rising prevalence (figures around 1 in 54–62 were discussed) mostly reflects broader diagnosis and longer survival; he's seen no convincing evidence of a true rise in incidence, though it is hard to prove.

• 09

  Vaccine hesitancy has become politicized.

  Starting around 2014–2015, the movement allied with 'health freedom' politics on the far right, after California tightened exemptions following a measles outbreak tied to Disneyland. A PBS/NPR/Marist poll found about 41% of white Republicans saying they wouldn't get a COVID vaccine, matching his Texas A&M collaborators' findings.

• 10

  Early-2021 COVID vaccines all performed well, with variant caveats.

  Pfizer's adolescent (12–15) trial had about 1,200 per arm, with 18 COVID cases in the placebo group and none vaccinated, high but small numbers. The B.1.1.7 variant (N501Y substitution) was covered well; the South African variant reduced protection, with AstraZeneca showing about 10% efficacy against mild-to-moderate disease. Hotez expected J&J might become two doses and boosters to be needed.

• 11

  Global vaccine supply is the next crisis.

  With 1.1 billion people in sub-Saharan Africa and 650 million in Latin America, Hotez feared the world had little for them. His team adapted their SARS/MERS work into a low-cost recombinant-protein COVID vaccine produced in yeast, like hepatitis B, scalable to around 100 million doses a month.